Granisetron is a medication primarily used to prevent nausea and vomiting caused by chemotherapy, radiation therapy, or surgery. It works as a selective serotonin 5-HT3 receptor antagonist, blocking serotonin's action, which can trigger vomiting.
Uses of Granisetron
- Chemotherapy-induced nausea and vomiting (CINV): Prevents nausea and vomiting associated with moderately to highly emetogenic chemotherapy.
- Radiation-induced nausea and vomiting (RINV): Manages nausea from radiation therapy.
- Postoperative nausea and vomiting (PONV): Used to reduce or prevent nausea after surgical procedures.
Dosage
Dosage may vary based on the condition being treated, the patient's age, and the route of administration. Common formulations include oral tablets, transdermal patches, and intravenous (IV) injections.
General Guidelines:
- Chemotherapy-induced nausea:
- Oral: 1 mg twice daily or 2 mg once daily, given up to 1 hour before chemotherapy.
- IV: 10 mcg/kg or 1 mg infused over 30 seconds, 30 minutes before chemotherapy.
- Radiation-induced nausea:
- Oral: 2 mg daily within 1 hour of radiation.
- Postoperative nausea:
- IV: 1 mg injected over 30 seconds before or after surgery.
Note: Always follow a doctor’s specific prescription, as these doses can vary.
Side Effects
Granisetron is generally well-tolerated but may cause some side effects:
Common Side Effects:
- Headache
- Constipation
- Fatigue or weakness
Serious Side Effects:
- Allergic reactions (rash, itching, swelling, or trouble breathing)
- Serotonin syndrome (confusion, rapid heart rate, high blood pressure, fever, sweating, or tremors)
- Changes in heart rhythm (QT prolongation)
If any severe side effects occur, seek immediate medical attention.
Precautions
- Allergies: Avoid if you are allergic to granisetron or similar medications.
- Heart Conditions: Use with caution in patients with a history of arrhythmias or those on medications prolonging QT interval.
- Pregnancy and Breastfeeding:
- Pregnancy: Use only if clearly needed; consult your doctor.
- Breastfeeding: It’s not known if granisetron passes into breast milk. Discuss with a healthcare provider.
- Drug Interactions:
- Use caution with medications that increase serotonin (e.g., SSRIs, SNRIs, or MAOIs) due to the risk of serotonin syndrome
Conclusion
Granisetron is a safe and effective medication for preventing nausea and vomiting associated with chemotherapy, radiation, or surgery. However, it should be used under medical supervision to manage potential side effects and interactions. Always follow the prescribed dosage and consult your healthcare provider for any concerns.